Renewable fuse element



1931. J. B. GLOWACKI 1,738,623

RENEWABLE FUSE ELEMENT Filed Aug. 1 F327 2 Sheets-Sheet l WI JEE Jan.13, 1931. .1. B. GLOWACKI 1,788,623

RENEWABLE FUSE ELEMENT Filed Aug. 11. 192'. 2 Sheets-Sheet 2 Patented.Ian. 13, 1931 v 4 UNITED STATES JOHN B. GLOWACKI, OF CHICAGO, ILLINOISApplication filed August 11, 1927. Serial No. 212,239.

knife blade type.

5 It is an object of this invention to provide a renewable fuse elementof an improved design or shape wherein theend forked sections aretapered outwardly providing an enlarged area adjacent the inner ends ofsaid sections where they connect up with reduced apertured fusibleconnecting sections of maximum current density so that the location offusing will be definitely located where a fusing section connects upwith the enlarged end of an end section due to the fact'that saidenlarged end of the' end section will cool more rapidly and prevent thefusing from extending outwardly to cause fusing of the fuse element withthe end of a knife blade with which therenewable fuse element isassociated.

It is a further object of this invention to provide an improvedrenewable fuse element having the end sections tapered to insure adefinite blowing of the fuse at reduced apertured fusing sectionswithout any apparent dan er of 'the fusing spreading to solder the orkedends of the fuse element to its mounting. o

It is an important object of this invention to provide a renewable fuseelement of either the single or multiple type with each of the fuseplates comprising a plurality of large sections joined by reducedapertured necks or fusing sections to insure a definite location atwhich fusingwill take place without danger of the fusing spreading dueto the fact that the portions of the end sections 'of a fuse connectedwith the fusing sections are considerably enlarged in area and taperoutwardly to the notched ends thereof to reduce the possibility of anyfusing taking place between the notched tapered ends of the renewablefuse element and the knife blade terminal members of the fuse.

Other and further important objects of this invention will be apparentfrom the disclosures in the specifications and the accompanyingdrawings.

This invention (ina preferred form) is RENEWABLE FUSE' ELEMENT PATENT;OFFICE I-SSUED illustrated,in the drawings and hereinafter more fullydescribed.

On the drawings:

Figure 1 is a side elevation of an improved fuse element embodying theprinciples of this invention and illustratingthe improved shape of theend sections.

Figure 2 is a top plan view of the renew able fuse element illustratedin Figure 1 showing the same to be of a dual type.

Figure 3 is a fragmentary elevational view illustrating a modified formof multi ple renewable fuse element associated with knife blademounting-elements.

Figure axis an elevational view of a modi- 5 fied form of multiple typerenewable fuse element adapted forhigh capacities and connected to knifeblade mounting units.

Figure 5 .is a side elevation of the high capacity renewable fusingelement illustrated in Figure 4.

Figure 6 is aside elevation of a modified type of the renewable fuseelement.

Figure 7 is a top plan view of the interior portion of a knife bladetype fuse unit ineluding a pair of dual type fuse elements 0 the typeillustrated in Figure 6.

Figure8 is a side elevation of still another type of renewable fuseelement adapted for high capacity work.

Figure 9 is a fragmentary elevational view of a fuse element mounting-ofthe knife blade type carrying a plurality of renew able fuse elements of(the type illustrated in F i ure 8. I

igur 10 is a side elevational view of still another type of renewablefuse element.

As shown in the drawings:

Figures 1 and 2 illustrate an improved renewable fuse element of thedual type wherein two fuse strips or elements designated as a whole bythe reference numeral 1 are constructed with their middle sectionsconnected to one another by means of a plurality of rivets 2 surroundedby insulating spacers or separating sleeves 3. Each of the improvedrenewable fuse plates or elements comprises a strip of suitableresistance material of low melting point consisting of an intermediateplate or section 4 and a pair of tapered end sections 5 provided withinsure fusing at a predetermined location.

The purpose of enlarging the inner end of the end sections 5 where theyjoin with the fusing sections 10 is to provide a larger cooling area ofmetal which acts to more definitely insure fusing to positively takeplace where said fusing sections 10 join the tapered ends 9 of the endsections. This construction tends to obviatespreading of the fusingoutwardly in the end sections toward the forked ends which are adaptedto be mounted in the knife blade supporting units forming part of acomplete fuse in which the improved renewable fuse elements are adaptedto be used. With the improved construction it will be noted that thetendency of the forked ends of the outer sections of the fuse element tobecome fused with the knife blade supports will be obviated, therebypermitting the end portions of a blown fuse to be readily removed fromits supports without any tendency of said supports being damaged byparts of a fuse element becoming fused therewith. Figure 3 illustrates amultiple type 'of renewable fuse element consisting of four fuse platesor elements similar in design and construction to that illustrated inFigure 1. The four plates are disposed in spaced parallel relation toone another and are connected against rotation with respect to oneanother by rivets on which insulating spacers or sleeves 3 areengaged tohold the fuse plates assembled in proper spaced relation to form a unittype multiple renewable fuse element in which a plurality of fuse platesof the required capacity are rigidly connected to be mounted as a unitwithout any danger of a person mounting fuse element plates of the wrongcapacity. This multiple type fuse element unlt permits a plurality'offuse element plates to be simultaneously mounted. Fi ure 3, furthermore,discloses a mounting unit at each end of the fuse element forming a partof a cartridge fuse of the knife blade type. The reference numeral 12indicates the inner end of a knife terminal having a stop plate or block13 rigidly secured at right angles thereto, leaving an inner extension14 of the knlfeblade on which a double screw member 1s rigidly supportedparallel to the stop block 13. Engaged on each end of the double screwmemher on opposite sides of the knife blade extension 14 is a flangednut 15 and an apertured metal spacer 16 one end of which is round whilethe opposite end is straight to contact and align itself against thestop block 13. The multiple type element is adapted to be removablyengaged as a unit on the double screw member with the forked ends of theend sections 5 of the fuse plates adapted to be separated by the knifeblade extension 14 and the spacers 16. The straight end edges 8 of thefuse plates are adapted to seat squarely against the stop block 13 afterwhich the retaining nuts 15 are tightened to hold the respective ends ofthe multiple type fuse element rigidly secured to its mounting. andproperly aligned therewith. The opposite end of the renewable multipletype fuse element is adapted to be similarly mounted in its knife bladetype of support.

Figures 4 and 5 illustrate a multiple type of renewable fuse elementadapted for high capacities and, furthermore, adapted to be properlyaligned between a pair of knife blade type supporting units of the typeillustrated and described in connection with Figure 3. In this typeof-renewable fuse element unit each of the fuse elements or platescomprises a pair of intermediate sections 17 connected by means of amiddle metal fusing section 18 having an elongated rectangular slot 19therein. Connected to the outer end of each of the intermediate sections17 is a tapered outersection 20 provided with an end notch 21 formingthe reduced end of the outer section into a fork having tines 22 withstraight transverse end edges 23. The enlarged inner end of each of theend sections is tapered at 24 and is integrally connected with itsrespective intermediate section 17 by means of a reduced fusing neck orsection 25 smaller than the middle fusing section 18 and having arectangular opening 26 therein.

Figures 6 and 7 illustrate another modified form of renewable fuseelement of a two plate type which consists of two renewable fuseelements each comprising an intermediate section 27 having. integrallyformed on each of the tapered ends thereof a re duced fusing section 28provided with a rectangular slot 29. One of the reduced fuse sections 28integrally connects up with the tapered end 30 of the enlarged end of atapered end' section 31 the outer end of which is rounded as at 32 and.is provided with 9. Ion itudinal central notch 33 to af, ford a for edend for the section. Integrally connected with the outer end of theother fuse section 28 is a tapered end 34 of a tapered end section 35the outer end of which is rounded at 36. Provided in one side of thetapered end section 35 is a shghtly curved transverse notch 37 whichforms the outer reduced end of the end section 35 into a hooked member.A pair of the fuse plates are adapted to be connected 1n spaced parallelrelation by a pair of rivets 4 insulating bridging pins 41. The ends ofthe insulating bar 40 are connected by means of plates 42 to a knifeblade extension 43 which is integrally formed 011 the inner end of aknife blade contact 44 and has a stop plate 45 rigidly mountedtransversely thereon. Mounted transversely on the knife blade extension43 is a double ended screw member on each end of which a movable spacer46 and a nut 47 is engaged. Rigidly engaged around the supporting screwand adjacent one ofthe respective plates 42 is a stationary spacer orwasher ring 48. To mount one of the renewable double type fuse elementson the mounting the notched end sections 31 are engaged over oneprojecting end of the screw and between the stationary washer 48 and thenut 47'. with the spaced end sections 31 positioned on opposite sides ofthe spacer 46. The fuse element is then pivoted so that the oppositehooked end thereof may be swung into engagement to hook over a screw onthe opposite end of the aligning bar 40 with the end sections 35separated by the respective movable'spacer 46. With the fuse elementmounted in place it is only necessary to tighten the nuts 47 toremovably hold the fuse element in place on its mounting. In this typeof fuse construction the two duplicate type renewable fuse elements areseparated by the insulating block or bar 40 and are spaced therefrom bymeans of the bridge pins 41 which serve to prevent contact of anoverheated fuse element with the bar 40.

Figures 8 and 9 illustrate a high capacity renewable fuse element of theduplicate type consisting of two fuse elements or strips each comprisinga pair of intermediate sections 49 connected by a reduced metal fusingsection or neck 50 having a rectangular opening 51 therein. Integrallyconnected to a tapered end 52 of one of the intermediate sections 49 isa reduced outer fusing section or neck 53 having a rectangular opening54 therein. The outer fusing section 53 integrally connects up with theinner tapered end 55 0f the enlarged end of a tapered end section 56 theouter end of which is rounded as at 57 and is provided with a middlelongitudinal notch 58 to form the rounded end into a forked member. In.-tegrally connected to the tapered end 59of the second intermediatesection 49 1s one end of a reduced neck or outer fusing section 60having a rectangular opening 61 therein. The other end of the outerfusing section 60 is connected to the tapered end 62 of an outer taperedsection 63 provided with a slightly curved transverse notch 64 in oneside thereof to form the outer end of said end section 63 into a hookedmember. In this high capacity type of renewable fuse element the twoduplicate type renewable fuse elements are connected to have theintermediate sections 49 of one plate connected to those of an oppositeplateby means of of renewable fuse element comprising an intermediatesection 69 having tapered ends 70 and side notches 71.- Integrallyformed on the middle portion of each of the tapered ends 70 of theintermediate section 69 is a reduced fusing section or neck 72 providedwith a rectangular slot 73. Integrally formed on the outer end of one ofsaid fusing sections 72 is the enlarged end of a tapered end section 74which is rounded at its reduced outer end as at 75 and is provided witha longitudinally disposed central notch 76. Integrally formed on theouter end of the other of said fusing action 72 is the enlarged end of atapered end section 77 rounded at its reduced outer end as at 78. Thetapered end section 77 is provided with a slightly curved transverselydisposed side notch 79 providing a hooked end for the fuse element.

The particular type of renewable self aligning fuse elements illustratedin Figures 1 and 5 are adapted for use in a fuse mounting wherein theknife blade type supporting units are connected to one another by meansclosed in Figure 6 to 10, inclusive, have the end section at one endthereof forked while the tapered end section at the other end is hookshaped due to the curved transverse notch which is provided therein.These renewable fuse elements may be used individually, in duplicate orin multiple, on fuse mounting devices, the end portions of which arepermanently connected by means of an insulation bar or block, as shownin Figures 7 and 9. The particular shape of the end sections of therenewable fuse elements permits the forked end section to be engaged onone of the supporting screws or bolts about which it may be pivoted sothat the hooked end section may be moved into hooked engagement with ascrew or bolt at the opposite end of the mounting. The

fuse element is adapted to be renewably se-- duced apertured sectionbetween each.slant ing end and said intermediate portion, each of saidsections being connected to the intermediate portion and the associatedend by upwardly and outwardly slanting sides for concentrating fuseblowing currents on the reduced and apertured sections.

In testimony whereof I have hereunto sub- D scribed my name at Chicago,Cook County,

Illinois. JOHN B. GLOlVACKI.

or parallel fusing sections assures a suiiiciently large area of thefuse element to melt under overload conditions to create a large gap.The peculiar tapered construction of i the-end sections of each fuseelement where they join the reduced apertured fusing sections areprovided for the purpose of affording a lar e area which will cool morerapidly after t e blowing of a fuse element so that the possibility ofthe fusing extending intb the end sections will be greatly reduced,thereby obviating the tendency of portions of said end sections frombecoming fused onto the mounting members so that they cannot be removedtherefrom without difliculty.

The improved renewable fuse elements, therefore, permit the resultantend portions of a blown fuse element to be readily removed fromtheirrespective mountings since the possibility of fusing taking placebetween the tapered end sections and the respective. mounting memberseliminated.

. I am aware that many changes may be made, and numerous details ofconstruction may be varied through a widerange without departing fromthe principles of this invention, and I therefore do not purposelimiting the patent granted hereon, otherwise than necessitated by theprior art.

I claim as my invention:

As an article of manufacture, a replaceable fuse element comprising astrip of fuse material having each of its ends formed to slant outwardlyin a direction toward the intermediate portion ofthe strip and a reispractically,

